LOINC Version 2.65 and RELMA Version 6.24 are now available

Download Current Versions

LOINC 2.77
Released 2024-02-27

RELMA 7.10
Released 2024-02-27

In this Update

We are delighted to present you with another feature-packed LOINC release. There's a lot to cover, but here's the outline:

  1. LOINC content highlights
    1. New content
    2. Content edits
  2. Highlights of updates to other LOINC release artifacts
    1. LOINC Answer File
    2. LOINC Display Name File
    3. LOINC Group File
    4. LOINC/IEEE Medical Device Code Mapping File
    5. LOINC Multiaxial Hierarchy File
    6. LOINC Part File
    7. LOINC/RSNA Radiology Playbook
  3. LOINC Linguistic Variant Updates
  4. Changes to the public LOINC data files in this release
    1. LOINC Table
    2. LOINC Panels and Forms File
    3. LOINC Top 2000+ Lab Observations
  5. RELMA release highlights
    1. Removed support for DOCUMENT_SECTION field
    2. Added support for the new LOINC DisplayName
  6. FHIR Terminology Services API

Read on for the full details.

Highlights from the latest LOINC release

Here we'll cover the important changes included in the current LOINC release.

As always, see the documentation included with each release artifact for more information.

New content

LOINC version 2.65 contains 89271 terms, an increase of 1408 since version 2.64. Overall, this release includes 513 new laboratory, 425 new clinical, 469 new survey and 1 new attachment terms.

Some of the new content highlights in this version:

  • Over 200 new microbiology terms, including 19 new panels
  • Approximately 130 new terms in both RAD and DOC.ONTOLOGY classes
  • Approximately 90 new terms in DRUG/TOX class
  • Over 60 new chemistry terms
  • Approximately 55 new serology terms
  • Thirty-eight new Patient-Reported Outcomes Measurement Information System (PROMIS) panels representing various adult, parent proxy, pediatric and cancer item banks and short forms
  • New terms for data elements included in the Centers for Disease Control (CDC) Public Health Emergency Operations Center (PH EOC) minimum data set (MDS) 89724-9. This is a work in progress; the full set of LOINCs is expected to be included in the June 2019 release.
  • New HEDIS 2019 Value Sets 90766-7
  • New version of the Inpatient Rehabilitation Facility - Patient Assessment Instrument (IRF-PAI) - version 3.0 89963-3
  • Orthodontic service attachment 90875-6 and over 20 new dental codes
  • New clinical and survey panels, including:
    • Pain intensity, Enjoyment of life, General activity scale 91148-7
    • Pressure Ulcer Scale for Healing Tool 3.0 90982-0
    • Patient-Oriented Eczema Measure 89862-7
    • Psoriasis care satisfaction questionnaire 90018-3
    • Fracture Risk Assessment (FRAX) 90264-3
    • Pulmonary Embolism Severity Index panel 89694-4
    • Routine Assessment of Patient Index Data 3 90028-2
    • Duke Anxiety Depression Scale 90854-1
    • Chronic Respiratory Questionnaire Self-Administered Individualized Format (CRQ-SAI) 89906-2
    • Chronic Respiratory Questionnaire Self-Administered Standardized Format (CRQ-SAS) 89905-4

Edits contained in this release

This release contains a total of 3054 deprecated terms, of which 98 were deprecated since version 2.64. In addition, about 6670 terms have been edited.

Changes based on internal review or as part of an ongoing project

  • The AnswerListType was updated from NORMATIVE to EXAMPLE for more than 200 terms because the Answers included in the lists are examples of the types of results that may be reported and not an exhaustive list. A few others were updated to PREFERRED because the list was relatively complete but could potentially change over time as new entities are discovered. For example, new species or subtypes of microorganisms or new hemoglobin types.
  • In the LOINC Document Ontology, Physician was dropped from Role values where the Role could be used across physician and non-physician specialties. For example, Physician resident is now just Resident. Additionally, Method of Social work was changed to Social worker based on the Clinical LOINC Committee approval to represent Social work/er as a Role in the LOINC Document Ontology.
  • For about 50 molecular resistance terms, updated the System from Isolate to Isolate/Specimen and Method from Probe.amp.tar to Molgen according to a more sustainable model for these terms [Approved by LOINC Laboratory Committee in June 2018].
  • Updated the PhenX ID from PhenX.<ID> to PX<ID> in the SURVEY_QUEST_SRC field for over 4000 terms to align with the variable identifier used in the PhenX Toolkit.
  • Changed the STATUS for six mass concentration chemistry terms from DISCOURAGED back to ACTIVE because at least two major laboratories are currently measuring this analyte in mass units.
  • Updated the Method for several terms from Thromboelastography to Thromboelastography.rotational to clarify that these assays use rotational TEG ("ROTEM") and to distinguish them from the original thromboelastography and new resonance thromboelastography methods.

Changes based on community input

  • 250 terms in the ALLERGY Class with a Property of Ratio but without a denominator were updated to a) include the denominator IgE.total in the Component and b) correct the Property to AFr to accurately reflect the meaning of the term.
  • Over 60 blood banking terms with NOS in the Component were deprecated because they were ambiguous.
  • Updated the OrderObs value for about 30 terms from Order to Both
  • Several terms for reporting mass or substance concentrations of combinations of drugs (e.g. Amoxicillin+Clavulanate or Trimethoprim+Sulfamethoxazole) were deprecated because each drug is typically measured and reported separately rather than as a combination.
  • A set of mass and substance concentration terms with the Components LDL 1, LDL 2, etc. were discouraged because they were being used incorrectly for reporting the amount of cholesterol contained in the LDL fraction, rather than the amount of the LDL fraction itself. We could not find any major laboratories who are reporting results for each LDL fraction. A replacement set of terms with Components Cholesterol.in LDL 1, Cholesterol.in LDL 2, etc. were created and the discouraged terms were mapped to the new terms as appropriate.
  • Consistent with Rosa's Law (Pub. L. 111-256), several terms were discouraged, and one term and Answer List were updated to replace the phrase mental retardation with intellectual disability.
  • 8-Estriol [Mass/​volume] in Urine 60549-3 was deprecated without a MapTo at this time since it is not clear what analyte was meant to represent.
  • The Method for two Reticulocytes terms, Reticulocytes [#/volume] in Blood by Manual count 40665-2 and Reticulocytes [#/volume] in Blood from Fetus by Manual count 66146-2 were updated from Manual to Manual count for consistency across terms.
  • Components Cytarabine C (e.g. in 53450-3) and Cytarabine U (e.g. in 53451-1) were updated to Cytarabine and Uracil arabinoside, respectively.
  • For Imipramine and Desipramine panel - Serum or Plasma 43123-9, the duplicate child element for Imipramine+Desipramine [Mass/volume] 9627-1 was removed and replaced with Imipramine [Mass/​volume] in Serum or Plasma 3690-5.
  • LOINC codes for Complement C3d+G (4493-3, 4494-1, 4405-8) and Complement C3d-c3d+Gg-IC3b receptors (6294-3, 4496-6) have been deprecated due to their ambiguity.
  • Several other minor content errors were corrected, including two terms with duplicate LONG_COMMON_NAME values (24910-2, 86402-5) and an error in the CONSUMER_NAME field (12841-3).
  • Several CLASS names in the Users' Guide Appendix B were updated for consistency with the corresponding Part NAME.

Updates to other release artifacts

LOINC Answer File

The release has been incremented from Beta.2 to Beta.3 VersionType. We have received no significant public comments about its structure and have not identified any major format changes needed at this time. However, we are not promoting this artifact to production status yet because we are still seeking user feedback on our approach for linking a single LOINC term to different answer lists in the context of different panels.

LOINC Display Name File

We have updated the LOINC Display Name File to Beta.1 VersionType because we received no significant public comments about its structure and have not identified any major format changes that are needed. In this Beta release, there are two primary changes:

  • The Property for quantitative terms has been moved to the end of the DisplayName and placed in square brackets. For example, 11-Deoxycortisol (24H U) [Moles/Vol]
  • The DisplayName for all Laboratory LOINC terms with a status of DEPRECATED is enclosed in angle brackets (<>). For example, <Casts LM.HPF #/area (Urine sed)>

We are pleased with the outcome of these Display Names, but continue to welcome your feedback.

LOINC Group File

This release has been upgraded to Beta.2 VersionType because we received no significant public comments about its structure and have not identified any major format changes that are needed.

In this release, 24749 unique LOINC terms are contained in one or more Groups. We have added content in several domains, including estimated fetal body weight and gestational age, pregnancy delivery date, pregnancy tests, and biochemical markers of smoking.

LOINC/IEEE Medical Device Code Mapping File

In this release we have added several new mappings, removed or corrected some mappings that were incorrect of linked to retired IEEE concepts.

LOINC Multiaxial Hierarchy File

LOINC terms that include a Challenge and/or a Method are being placed in the hierarchy based on Component alone instead of Component + System. We plan to address this issue for the next release.

LOINC Part File

This artifact remains Beta.2 VersionType. We have received no significant public comments about its structure and have not identified any major format changes needed at this time. We are continuing to evaluate our approach to linking LOINC Terms to Parts, including for suffixes, divisors, and core components. Before moving to production status, we would like further testing and feedback about these approaches.

In this release, some terms contain multiple Component Parts with a LinkTypeName of Primary.

LOINC/RSNA Radiology Playbook

The release of the LOINC/RSNA Radiology Playbook file represents the success of our ongoing collaborative work with the RSNA to develop a unified model for naming radiology procedures. all of the existing LOINC radiology content has been transformed into the unified model and all of the core RadLex Playbook terms are now linked to corresponding terms in LOINC.

The mappings to and content from the RSNA Playbook are based on version 2.4 of that terminology, and Radiology Part mappings are based on RadLex version 3.15.

Some terms with multiple Aggregation values have one or more Aggregation values that are not being assigned the correct PartSequenceOrder number.

A small number of LOINC Radiology Parts that do not have mappings to RadLex RIDs. We plan to address these issues for the next LOINC release.

LOINC Linguistic Updates

The global community of LOINC users continues to help produce a wonderful collection of translations. These linguistic variants (we support multiple translations of the same language) are available in RELMA, the online search.loinc.org application, and in the LOINC Linguistic Variants File.

Updated Linguistic Variants in this release:

  1. es_ES_12 - Spanish (SPAIN)
  2. nl_NL_22 - Dutch (NETHERLANDS)
  3. fr_CA_8 - French (CANADA)
  4. fr_FR_18 - French (FRANCE)
  5. it_IT_16 - Italian (ITALY)
  6. zh_CN_5 - Chinese (CHINA)

Users should note that we intend to retire the translations produced by CUMUL in a future release. That translation effort was suspended many years ago and more comprehensive translations into French, German, and Italian have been produced by others.

Notice of changes to the public LOINC data files in this release


As previously announced, we have implemented the following change to the LOINC Table (all formats):

Formal Definition: Classification of whether this LOINC code can be used a full document, a section of a document, or both.
Action: DELETE

LOINC Panels and Forms File

The Panels and Forms File has been incremented from version 2.64 to 3.0 to reflect structural changes to the file as follows. The PanelsAndForms Excel spreadsheet was replaced by a comma separated value (csv) file in order to provide better consistency across our release artifacts. In this release, we have also bundled together the Loinc.csv, AnswerList.csv, and LoincAnswerListLink.csv files with the PanelsAndForms.csv file to provide additional information about LOINCs, Answer lists, and Answer strings that is not contained in the PanelsAndForms.csv file alone. We felt that this more complete package of content would be more useful to implementers.

The PanelsAndForms.csv file contains the same fields as the FORMS tab of the prior spreadsheet, except for omitting the four fields listed below:

  • SkipLogicTarget
  • SkipLogicTargetAnswer
  • AnswerRequired
  • MaxNumberOfAnswers

We had previously announced the pending removal of these fields when LOINC version 2.48 was published, and they were supposed to be removed in version 2.52. However, they were not actually removed until this current release (3.0).

LOINC Top 2000+ Lab Observations

As previously announced, the LOINC Top 2000+ Lab Observations File and Mapper's Guide will no longer be updated. However, they are still included in this release (in their frozen state). We continue to explore new ways to present a common subset of LOINC terms based on more recent lab test frequency data.

RELMA version 6.24

Removed support for DOCUMENT_SECTION field

The DOCUMENT_SECTION field has been removed from the LOINC Table in version 2.65. Correspondingly, we have eliminated the DocSection search field from RELMA.

Added support for the new LOINC DisplayName

We have added support for display and searching of the new LOINC DisplayName. See the Advanced Search Syntax section of the on-line help for an example of using this new field.

With the addition of this new field RELMA now requires a minimum database version of 2.65 (this current release). Older versions of the database will not work with this version of RELMA.

The RELMA database and Lucene indexes contain LOINC Parts and Answer lists that may not be used by or linked to any LOINC terms, and you may see them returned in RELMA search results on the Part search tab and Answer list search tab. These Parts and Answer lists may have been used in the past or might not have ever been used. They are not included in the Part and Answer list release artifacts, and this discrepancy has been a source of confusion for some users. We are planning to remove these unused Parts and Answer lists from RELMA in a future release.

FHIR Terminology Services API

Updated LOINC content available programmatically

During our release process we have also updated our FHIR terminology server with the latest content. The server currently supports CodeSystem, ValueSet, and ConceptMap resources. Read more at loinc.org/fhir.